[deleg] add support for DELEG type

Signed-off-by: Manu Bretelle <chantr4@gmail.com>

svcb.go

@@ -240,6 +240,24 @@ func (rr *HTTPS) parse(c *zlexer, o string) *ParseError {
 	return rr.SVCB.parse(c, o)
 }
 
+// DELEG RR. Everything valid for SVCB applies to DELEG as well.
+// Except that the DELEG record is intended for use with the DELEG protocols.
+//
+// NOTE: The HTTPS/SVCB RFCs are in the draft stage.
+// The API, including constants and types related to SVCBKeyValues, may
+// change in future versions in accordance with the latest drafts.
+type DELEG struct {
+	SVCB
+}
+
+func (rr *DELEG) String() string {
+	return rr.SVCB.String()
+}
+
+func (rr *DELEG) parse(c *zlexer, o string) *ParseError {
+	return rr.SVCB.parse(c, o)
+}
+
 // SVCBKeyValue defines a key=value pair for the SVCB RR type.
 // An SVCB RR can have multiple SVCBKeyValues appended to it.
 type SVCBKeyValue interface {

types.go

@@ -85,6 +85,7 @@ const (
 	TypeZONEMD     uint16 = 63
 	TypeSVCB       uint16 = 64
 	TypeHTTPS      uint16 = 65
+	TypeDELEG      uint16 = 66
 	TypeSPF        uint16 = 99
 	TypeUINFO      uint16 = 100
 	TypeUID        uint16 = 101